AQUA-CHEM FRESHWATER GENERATORS Builder of water processing systems in USA since 1929 – and trusted for diverse extreme applications from military to offshore, Aqua-Chem is the leading water treatment company in the world, providing complete range of thermal and membrane treatment technologies.

Aqua-Chem’s vapor compression distillation watermakers provide reliable, proven solutions for offshore desalination of seawater, killing bacteria and removing suspended solids, dissolved minerals and organic contaminants. These units are designed to operate in the challenging conditions encountered in offshore operations, and are backed by decades of successful operating history. Our vapor compression distillation watermakers consistently produce purified water with less than 5 ppm of total dissolved solids.

Design Features

Evaporator – The evaporator features a horizontal design using the patented Spray-Film® process. In use for over 40 years now, this technology continues to be the design of choice in conditions that demand maximum reliability, lowest operating costs and maximum production.

Automation – Watermakers are designed to operate automatically with a pushbutton start. A programmable logic controller (PLC) and human machine interface (HMI) are standard.

Insulation – The evaporator is insulated with fiberglass and covered with aluminum cladding.

Benefits

From the North Sea to Southeast Asia, you can count on crystal-clear water at the rated capacity, confident that performance, capacity and water quality are not affected by feedwater characteristics.

Custom engineering is available to meet international electrical codes, rig specifications and unique operating conditions.

Patented Spray-Film evaporator design provides improved wetting of the tube bundle which minimizes scaling. This means less downtime for cleaning and less chemical use.

Spray-Film design also includes built-in, on-line cleaning for removing any scale, reducing maintenance costs and increasing operating life.

The most reliable steam compressor design incorporates a unique journal bearing with thin film technology for long-lasting performance, which is superior to ball bearings.

Simple layout improves safety and ease of maintenance to extend operating life. All major components are accessible from floor level, with the compressor and pumps located at the edge of the skid for easy serviceability.

Easy, low-cost installation, with only five piping connections and one electrical connection.

Reliable and durable materials with proven performance after more than four decades of offshore use by Aqua-Chem.

Factory tested to ensure trouble-free startup.

Efficiency is 0.05-0.07 kw per gallon of purified water produced.

Operating Characteristics

Model

Type

Rate

SR200

SR300

SR400

SR600

SR700

Flows

Feedwater

Gallons Per Hour

400

600

800

1200

1400

Cubic Meters PerDay

36.4

54.5

72.7

109

127

Blowdown

Gallons Per Hour

200

300

400

600

700

Cubic Meters PerDay

18.2

27.3

36.4

54.5

63.6

Distillate

Gallons Per Hour

200

300

400

600

700

Cubic Meters PerDay

18.2

27.3

36.4

54.5

63.6

Power

Motor Size
Horsepower

Compressor

20

30

40

50

60

Rec. Pump

3

3

5

7.5

7.5

Dist. Pump

2

2

2

2

2

Lube Oil

0.5

0.5

0.5

0.5

0.5

Electric Heaters
Kw

With Plate Type
Heat Exchanger

(3) 9

(3) 9

(3) 12

(3) 12

(3) 12

Motor Operating
Power at Rated
Capacity Kw/Hr

Compressor & Pumps

16

21.5

30

39.5

43

Heat

Make Up Heat
Requirements

Electrical (Kw)

12

14

14

18.5

18.5

Steam Lb/Hr

42

50

50

65

68

Steam Kg/Hr

19

23

23

30

32

Operating
Load

All Electric Unit

Kw - Hr / Hr

28

35.5

44

58

60.5

Steam Make Up
Heat

Kw - Hr / Hr

26

21.5

30

39.5

44.5

Total
Connected
Load

Electric Motor
Drive w/Steam
Make Up Heat

Kw

18

25.5

34.5

44.7

53

All Electric

Kw

45

52.5

70.5

80.7

89.1

Economy

All Electric

Kw - Hr / 1000 gal.

140

118

110

96

95

Specific Energy

Btu/Lb of Product Water

57

48

45

39.4

38.5

Notes:

Above power and steam requirements at a feedwater temperature of 60° F / 16° C.

Vacuum Evaporation Technology – Vacuum evaporation technology reduces the boiling point of the water to less than 150° F, which helps to retard the formation of scale while concurrently increasing the running time between maintenance and cleaning.

Custom Design – Our units can be easily customized to comply with standards established by CE, ABS, DNV and others. The flexibility to make modifications to meet your specific requirements helps set us apart in the industry.

Materials of Construction – Our components are made of the strongest, most durable materials available to extend system life. Evaporator shells include 90/10 copper nickel or stainless steel, while our evaporator tubes are made with titanium and copper nickel, or duplex stainless steel and aluminum brass. All the piping in our vacuum vapor compression distillers consists of copper nickel, stainless steel or bronze.

Distillation can be used in any seawater condition, regardless of salinity, temperature or silt. Distillation produces the most consistent, high-quality water, with less than 5 ppm total dissolved solids (TDS).

Aqua-Chem distillers have set the standard for innovations that reduce maintenance costs and downtime, while increasing operating life. We have units that continue to provide excellent service after more than 30 years of operation. Over the years, continual improvements have solidified our reputation as the most innovative designer of offshore desalination equipment.

All Aqua-Chem vacuum vapor compression distillers use our patented Spray-Film evaporator design which provides improved wetting of the tube bundle and reduced scaling compared to rising film or plate-type designs. This results in less downtime for cleaning. The Spray-Film design also includes built-in on-line cleaning for removing scale, thus avoiding any disassembly or manual cleaning.

Aqua-Chem distillers offer improved safety and ease of maintenance with all major components readily accessible from the deck level. The compressor and pumps are specifically located at the edge of the skid for easy serviceability, encouraging regular maintenance and ensuring a long operating life.

How Aqua-Chem Spray-Film® Vacuum Vapor Compression Works

Incoming feedwater is preheated by the outgoing blowdown and distillate. Feedwater and recirculation water are combined and sprayed over the evaporator tube bundle. Start-up/ make-up steam is produced in the evaporator boiler. A portion of the spray is evaporated as pure steam and the remainder is collected in the sump to be further recirculated. Some of the collected water is discharged as blowdown to maintain the desired brine concentration. Steam generated inside the evaporator is drawn through the demisters by the centrifugal compressor, and is superheated to 250° F in the compression process. The steam condenses inside the evaporator tube bundle and is collected as pure distillate. The distillate is pumped through the heat exchanger and into storage. Vapor compression is significantly more energy efficient than other distillation methods because energy is recycled back into the process.

Equipment Characteristics

Model

Capacity
Tons/Day

Dimensions (Inches)

Weight
(Lbs)

Length

Width

Height

SV30

30

87

116

115

10,000

SV50

50

87

116

115

15,000

SV70

70

87

140

115

18,000

Aqua-Chem is well known in the marine industry for supplying seawater distillers that use waste heat from diesel engine jacket water or other sources to desalinate seawater. In many cases, this wasted energy can be used to make water with little or no additional energy input. Our waste heat units are in service on offshore oil rigs, naval vessels and merchant ships, and have provided years of efficient service. These units consistently produce purified water with less than 5 ppm of total dissolved solids.

Design Features

Heat Source – Diesel engine jacket cooling water is used to supply heat to the unit. Use of waste heat requires little or no additional energy input. If necessary, supplemental steam or electric heat can be provided to compensate for insufficient heat during low engine load operations.

Materials of Construction – We use corrosion-resistant duplex stainless steel, copper-nickel and stainless steel for the shell and piping, and titanium plate packs for the heat exchanger.

Automation– Watermakers are designed for simplicity of operation. Units are controlled by manual startup and shutdown with automatic operation. Product water is continuously monitored with automatic diversion if salinity exceeds programmed limits.

Compact units with simple operation, only one pump is required to operate.

Use of waste heat requires little or no additional energy input.

Low-temperature operation reduces corrosion and scaling potential.

Custom engineering is available to meet international electrical codes, rig specifications and unique operating conditions.

Unit operates automatically after startup with minimal supervision.

Easy, low-cost installation, with only five piping connections and one electrical connection.

Reliable and durable materials with proven performance after more than four decades of offshore use by Aqua-Chem.

DNV/ABS/NR-13 compliance.

Double-effect watermakers are also available when waste heat availability is limited.

Factory tested to ensure trouble-free startup.

How Aqua-Chem Seawater Plate Distillers Work

Seawater first passes through the condenser on one side of each plate in the upper plate pack. It condenses the water vapor into distilled water on the other side of each plate.

About 10 percent of incoming seawater is then diverted to the evaporator or lower plate pack of the distiller.

The heating water from the waste heat source passes through the evaporator and heats the seawater to boiling. Since the unit operates at a vacuum, the seawater boils at 50° C to 60° C.

The water vapor rises toward the top of the unit and passes through a wire mesh mist eliminator before entering the upper plate pack and condensing into distilled water.

Distilled water collected in the upper plate pack drains to the distillate pump. Before being pumped to the storage tank, the conductivity is continuously monitored and automatically dumps to drain if the conductivity is too high.

The bulk of the seawater flows through the eductor. The seawater drives this suction device which draws vacuum, removes air and gases from the water vapor, and removes concentrated seawater from the bottom of the distiller.

Equipment Characteristics

Model

Capacity
(m³/day)

Heat
Required
(kW)

Dimensions (mm)

Weight
(kg)

Length

Width

Height

Single Effect (two plate packs)

SPD13-10

10

350

1,100

1,300

1,600

500

SPD13-25

25

750

1,400

1,300

1,600

550

SPD22-30

30

1,050

1,200

1,600

1,700

1,000

SPD35-40

40

1,400

1,700

1,600

2,400

1,400

SPD35-50

50

1,750

1,700

1,600

2,400

1,500

SPD35-60

60

2,100

2,000

1,600

2,400

1,900

Double Effect (two plate packs)

SPD235-40

40

1,000

2,400

1,800

3,200

2,700

SPD235-60

60

1,400

2,800

1,800

3,200

2,900

Aqua-Chem provides a full range of reverse osmosis systems for offshore oil, gas and drilling customers. Our systems have provided potable water for more than 20 years and are in service around the world. Each reverse osmosis system affords low initial cost and economical life-cycle operating costs.

Design Features

Sized to fit in minimum space. Modular, 2 and 3 piece options available to facilitate installation.

Robust skid & frame. Can be turned on end to pass through vertical hatch openings. Top side lifting lugs. Frames coated for offshore service.

PLC Control of start-up, backwash, shutdown and alarm sequences of operation

Desalination by Reverse Osmosis (RO) is a process whereby fresh water is extracted from seawater through the use of a semipermeable membrane. An RO watermaker consists of several key components. Prefiltration removes particulate matter from the seawater. Then, a high-pressure pump pressurizes the seawater to approximately 800-1,000 psi. Pressure vessels house the RO membranes where the separation of fresh water from seawater occurs. Approximately 40 percent of the seawater feed is extracted as fresh product. The balance of the water, referred to as “concentrate,” is discharged to drain. A real-time conductivity instrument measures the conductivity of the product water. If the maximum conductivity limit is exceeded, product water is automatically diverted to waste.